Or as i call them by their technical name thingamabobs. These were made on my Harrison M250 lathe converted to CNC.
Control software Mach3, Cad/Cam OneCNC
http://www.youtube.com/watch?v=1UWrYydJG0Q
Phil
Printable View
Or as i call them by their technical name thingamabobs. These were made on my Harrison M250 lathe converted to CNC.
Control software Mach3, Cad/Cam OneCNC
http://www.youtube.com/watch?v=1UWrYydJG0Q
Phil
what are they for?
it does look like you can have hours of fun with them :rofl:
Nice, they look like fun!
Nice...I once made cylindrical version of that.
How did you hold it in the chuck? Soft jaws machined to fit?
Very effective, though kind of cheating rolling them with one soft surface.
Well i don't know about hours, few minutes maybe. They have been made for someone to use in demonstrations and have some fun.Quote:
Originally Posted by h4ppy-chris
They are cylindrical, no i didn't use soft jaws and i am rolling them using shiny clear perspex which is nice and hard.:eek: :smile:Quote:
Originally Posted by Jonathan
Phil
Hmm, so did you machine them all in one operation? Or are you not disclosing how :naughty: I saw the other thread about it here a while ago.Quote:
Originally Posted by M250cnc
By cylindrical I mean mine were just prisms. I did it in the lathe by offsetting the center and machining it three times.
Exactly - now use two pieces of perspex. That would be even more impressive.Quote:
Originally Posted by M250cnc
The shapes are for me. They look awesome! Looking forward to the postman knocking.
Here's a little blog post I wrote about shapes and solids of constant width :
http://blog.stevemould.com/50p-coins-make-great-wheels/
Sent from my Nexus S using Tapatalk
My approach would be to turn the pointy bit and then basically part off the lightly curved face first roughing a relief down to maybe 10mm dia and then finishing the face and parting off the final 10mm in one go - if you get the tool shape right it should work ok.Quote:
Originally Posted by Jonathan
Anywhere near? :-)
I thought it might be that, but there's no mark at all at the center of the lightly curved face.Quote:
Originally Posted by FatFreddie
Thanks Phil & Steve. The video is brilliant!
More here on these curves.
HTH
John
Maybe, getting warm :lol:Quote:
Originally Posted by FatFreddie
It will make it interesting for those that watch but do not participate in the threads to see how various minds work.
The piece is 48mm diameter and will not go through the headstock of my lathe.
So material cost has to be considered, it is not a secret in how i did it but just a bit of fun not to give the game away too easily. But i will let on if anyone gets close to my method.
Phil
Jonathan i have never heard anyone call a prism cylindrical before. :lol:Quote:
Originally Posted by Jonathan
I would have tried rolling them on two pieces of perspex but as i made them for a customer i can't really get them all scratched can i.
They are on a thick towel as i was using a glass table and didn't want to explain to her indoors about any accidents. :whistling:
Phil
John Thanks for the comments and the link.Quote:
Originally Posted by z3t4
Phil
Nor have I heard anyone call a solid of constant width a cylinder, but nevermind - I should have chosen a better word!Quote:
Originally Posted by M250cnc
They must be aluminum then if there's a risk of getting them scratched.
Still thinking ...
Jonathan, Steve Mould called them Constants of Solid Width, i call em thingamabobs.Quote:
Originally Posted by Jonathan
You are correct in that they are made from Aluminium.
They are very round as you can see from this poor photo, so cylindrical to me. :lol:
Phil
Maybe when parting off you held the piece in a revolving chuck in the tailstock. That would still leave a mark, so take that chuck and put it on the spindle and machine the other side? It should still be on center so that could work ... probably something a bit more ingenious though :smile:
Possible some sort of turning between centers was used ('save material').
I guess the question to ask is was it all machined in one operation or not?
Very cold. :lol:Quote:
Originally Posted by Jonathan
Clues, not every one had the same operations there are some subtle differences, so you now know there is more than one operation. :naughty:Quote:
Originally Posted by Jonathan
:whistling: I'm enjoying this. :smile:
Phil
http://www.youtube.com/watch?v=cUCSSJwO3GU
Shapes and Solids of Constant Width - Numberphile - YouTube
this site has become youtube famous,
who said it couldn't be done?
and who did it in the end?
interesting video also.
WoooHooo :yahoo: we're famous :excitement:
.Me